Medulloblastoma is one of the most common types of cancerous brain tumour wherein the proliferation of cancer cells usually happens in the lower back part of the brain, called the cerebellum and the posterior fossa. It is categorized as a type of embryonal tumor (i.e., a tumor that starts in the fetal (embryonic) cells in the brain). These are chiefly invasive, rapidly growing in nature, unlike most brain tumors, and usually spread through the cerebrospinal fluid (the fluid that surrounds and protects the brain and spinal cord) to other areas around the brain and spinal cord and frequently metastasize to different locations along the surface of the brain and spinal cord. But it is unusual for medulloblastomas to spread outside the brain and spinal cord. Although it can occur at any age, it is more commonly noticed in children and younger adults.
Depending upon the different types of genetic mutations, medulloblastoma is classified into 7 types, mainly:
- Classic medulloblastoma
- Large-cell or anaplastic medulloblastoma
- Medulloblastoma with glial differentiation
- Medulloblastoma with neuroblastic or neuronal differentiation
- Melanotic medulloblastoma
- Desmoplastic nodular medulloblastoma
Just like any other form of cancer, the exact cause of medulloblastoma is yet unknown, but several research and studies suggest that it usually forms when there is a genetic mutation in the cells of the cerebellum leading to a rise of abnormally shaped cells that do not die and keep accumulating to form tumour-like structures. Although medulloblastomas are believed to originate from immature or embryonal cells at their earliest stage of development, the cell of origin depends on the subgroup of medulloblastoma.
Certain causative factors that increase the risk of medulloblastoma includes:
Age: Although it can occur at any age, it is more common in children below 6 – 8 years of age.
Gender: Boys are more prone to medulloblastoma than girls.
Genetics: Though this type of brain cancer is not inherited, yet syndromes such as Gorlin's syndrome or Turcot's syndrome or Nevoid basal cell carcinoma syndrome might increase the risk of developing medulloblastoma.
These malignant cells grow and spread very quickly and the signs and symptoms include:
- Changes in behaviour
- Changes in appetite
- Problems with vision like double vision
- Problems with handwriting and other motor skills
- Nausea or vomiting
- Back pain
- Inability to control the bowels and bladder
- Difficulty walking
Diagnosis And Treatment
On noticing any of the above-mentioned signs and symptoms, consult a doctor at once to start the treatment at the earliest. The specialized doctor or neurologist usually does a thorough physical check-up, acknowledges the patient’s family history and past medical history and does a series of diagnostics which include:
Neurological Exam: The doctor asks the patient to move around to analyses your vision, hearing ability, coordination, balance, strength and reflexes.
Imaging Techniques: This includes CT-scan, MRI-scan, PET-scan and Ultrasound to find the exact position of the tumour.
Lumbar Puncture: Also known as Spinal Tap, the procedure involves removal of cerebrospinal fluid for testing.
Biopsy: A mass of tissue from the tumorous growth is analyzed to determine the types of cells and their level of aggressiveness.
Treatment options usually include a team of doctors consulting to perform the best possible option to bestow the patient with a normal life. It is usually selected based upon the type, stage of cancer, location of the tumor and other factors like overall health, age, of the patient and sensitivity to certain medications. This includes:
- Surgery (includes removal of tumour and to relieve fluid build-up in the brain)
- Radiation therapy
- Clinical trials